On soil

Soil is a key world reserve and agriculture has an important role to play in protecting it.

Soil degradation through nutrient depletion has been implicated in the decline of earlier civilisations. Even the growth of legumes and careful husbandry of manures cannot prevent eventual depletion as inevitable leaching and erosion steadily lose phosphate, potash and other nutrients.

The problem of soil degradation is covered in detail in Agriculture, Fertilizers and the Environment written by a team of Yara researchers with contributions from recognised scientists from all over the world. We produced this book - first written in 1990 and restricted to European conditions, and updated and published as a second edition from a global perspective in 1999 – with the purpose of providing a balanced scientific review of the environmental and sustainability issues relating to fertilizer use, and how its environmental impact can be minimised.

Sustainability of soils.

It is only in the last 160 years, with the invention of mineral fertilizer, that long-term nutrient depletion has been able to be prevented anywhere through the addition of crop nutrients to agriculture. Long-term field experiments, such as those at Rothamsted in the UK that began in 1843, have demonstrated the beneficial effects of fertilizer use on soils. The higher yields achieved through optimum mineral fertilizer use are associated with greater amounts of crop residues such as straw, roots and leaves. These residues add organic matter so helping to maintain soil quality. Long-term fertilizer use tends to increase soil organic matter content.

The role of mineral fertilizer.

Yara contributes to the long-term sustainability of soils through developing a wide range of mineral fertilizers to meet individual crop needs

Agriculture, Fertilizers and the Environment. M Laegrid, O C Bockman and O Kaarstad. CABI Publishing, 1999, 294pp, ISBN 0-85199-358-3.